1. Field of the Invention
The present invention concerns a non-stick chewing gum base composition which is free from fats, waxes, and elastomer plasticizing materials known as elastomer solvent resins, and a chewing gum composition prepared using the gum base.
2. Description of the Background Art
Chewing gums are conventionally prepared by adding sweeteners, flavoring agents and the like to a chewing gum base. Conventional gum bases normally contain, as a principal ingredient, any of a number of different resinous gum materials such as: (1) natural rubber elastomers (e.g., rubber latex, guayule, and the like); (2) natural gum elastomers (e.g., chicle, jelutong, balata, guttapercha, lechi caspi, sorva, pendare, perillo, leche de vaca, niger gutta, tunu, chiquibul, crown gum, and the like); (3) synthetic rubber elastomers (e.g., styrene-butadiene rubber, polyisobutylene, isobutylene-isoprene copolymers, polybutadiene, and the like); (4) hydrophobic synthetic polymers (e.g., polyvinyl acetates, ethylene/vinyl acetate, vinyl laurate/vinyl acetate copolymer, and the like); and (5) mixtures thereof. Other functional ingredients are typically present in conventional chewing gum bases to modify and tailor the overall properties of the resulting chewing gum, such as one or more of fats, waxes, elastomer solvent resins, fillers, softeners, emulsifiers, plasticizers, antioxidants, etc. The particular combination of ingredients used in a chewing gum base depends on factors such as the particular kind and amount of resinous gum material employed and the overall desired texture and consistency characteristics of the resulting chewing gum composition (e.g., chew, stickiness, flavor release, springiness, film forming characteristic, elasticity, etc.).
Fats, waxes and elastomer solvent resins aid in softening and plasticizing the resinous gum material and also provide other desirable properties. For example, fats provide chewing gum smoothness, waxes improve the elasticity of its chew character, and elastomer solvent resins provide it with chew bulkiness. However, fats, waxes, and elastomer solvent resins also adversely affect the characteristics of the chewing gum; for example, they result in increased stickiness and reduced flavor release. For example, fats such as hydrogenated or partially hydrogenated vegetable oils including cottonseed and soybean oils, hydrogenated or partially hydrogenated animal fats, cocoa butter, and the like reduce the viscosity of the gum base, causing it to become sticky. Waxes such as paraffin wax, microcrystalline wax, petroleum wax, natural waxes, and the like also result in more stickiness. Elastomer solvent resins used as softeners and tackifiers for the resinous gum material, such as methyl, glycerol, or pentaerythritol esters of rosins or modified rosins, including hydrogenated, dimerized, or polymerized rosins, terpene resins including polyterpene and polymers of alpha-pinene or beta-pinene, and the like, also contribute to tackiness. As a result, conventional chewing gums have been criticized by some who believe that gums that have been consumed and improperly discarded pollute the environment by sticking to the surfaces on which they have been deposited.
Because conventional chewing gums adhere strongly to a variety of surfaces including wood, floors, asphalt pavement, concrete, carpet, leather, hair, and cloth, discarded chewing gums that are stuck to those surfaces are often difficult and costly to remove. Oftentimes, even after the chewing gums have been removed, stains are left on the surfaces. As a result, vendors have been banned from selling conventional chewing gums to consumers in many public places such as train stations, arenas, amusement parks, and schools. The country of Singapore has flatly banned the selling of chewing gums. Accordingly, a chewing gum that is easily removable from the surfaces on which it is discarded or deposited would be highly desirable.
Conventional chewing gums that have non-stick characteristics are typically designed not to adhere to natural teeth and synthetic dental products during chewing. These chewing gums, however, still adhere to other surfaces when they are discarded. For example, U.S. Pat. Nos. 3,984,574, 4,357,355, 4,518,615, and 5,266,336 disclose non-tack chewing gum compositions that do not adhere to dentures, fillings, or natural teeth, but none-the-less stick to other surfaces.
U.S. Pat. Nos. 4,794,003 and 4,721,620 disclose bubble gum compositions that do not stick to the face. These compositions, however, contain waxes, fats, and elastomer solvent resins.
U.S. Pat. No. 5,116,626 discloses a transparent gum base composition containing a variety of ingredients such as synthetic rubber elastomers, polyvinyl acetates, softeners, and fillers, and optionally fats, waxes, and elastomer solvent resins.
U.S. Pat. No. 3,285,750 discloses a chewing gum composition that is said to have low adherence to various surfaces. However, that chewing gum composition must contain a resinous adhesion resistant agent in powder form.